Error 13 typically means there is a network connection issue to the target machines. A good test to run would be to start a continuous ping to that machine from the console machine. While this is running, kick off a scan. If you get an error 13 in the scan, then likely you will see a dropped connection to that machine in the ping. This could be caused by network connectivity issues, faulty NIC, Wireless connections, etc. You could also run wireshark or another network monitoring tool during scans if you want to look for more in depth information.

Some things to look into:

-Is this a wireless connection? If so, can you try using the NIC to connect and see if you still get the same error?

-Is there anything unique about how this machine connects vs the working machines?

We just migrated to Ivanti Patch 9.3.0 and started having the same scan error on 13 of 194 systems - not sure why it started but deleting the registry node at HKLM\software\wow6432node\Microsoft\Update\Shavlik92 allowed all 13 to be successfully scanned, no reboot required.